Figure 2. LTPP data collection and data movement
flowchart. Flowchart. The figure consists of a flowchart showing seven data
types being collected. Deflection data first is collected with the falling
weight deflectometer (FWD) and then goes through field control. The data then
is sent to the regional offices where the quality control (QC) is done with FWD
scan software, after which, data may be edited. Data is then loaded into the
Regional Information Management System (RIMS) database. Longitudinal profile
data is collected with the profilometer, and then it goes through field control
by checking on International Roughness Index (IRI) variability. The data is
then sent to the regional offices, where it is put through PROFCHK software to
recompute profile parameters and to perform QC, after which, some profiles may
be eliminated. The data then is loaded into the RIMS database. Transverse
profile data is collected with both dipstick and film. Dipstick data is put
through PROFCHK software by the regions, where some profiles may be eliminated.
Film data is analyzed and electronically stored before being sent to the
regional offices. All transverse profile data then is loaded into the RIMS
database. Distress data is collected both manually and photographically. Manual
data is reviewed and entered by the regional offices and then loaded into the
RIMS. Photographic data is sent directly to the regional offices and then
loaded into the RIMS. Climatic data, is collected at Automatic Weather Stations
(AWS), either downloaded by modem or during site visits. The data is then
reviewed with AWS check software. The data then is checked, extracted, and
loaded into the RIMS. Traffic data is collected by weigh-in-motion (WIM)
equipment and automated vehicle classification (AVC). Data is entered into the
Regional Traffic Database. The QC then is performed and data is flagged. All
data is entered into the Central Traffic Database. All traffic data deemed
acceptable is used to compute summary statistics, and then the statistics are
entered into the RIMS. Materials data is obtained from field and laboratory
tests. Coring and sampling is done and tested by the Long-Term Pavement
Performance (LTPP) program and State agencies. Test data and data forms are
forwarded to the regional offices. For in-situ field testing, test data and
data forms are forwarded to the regional offices. All materials data is then
reviewed by the regional offices and converted to machine-readable form before
being loaded into the RIMS. All of the seven data types loaded into the RIMS
are run through a series of data-specific QC programs. Manual data upgrades are
performed by the regions, if appropriate, and then loaded into the national
Information Management System (IMS) database. Data that makes it to level E is
released to the public.

Figure 3. Thickness histograms for the thin HMA layer
(102 millimeters) from tables SPS1_LAYER (construction data) and TST_L05B.
Graphs. The figure consists of two bar graphs. The first graph shows
construction of 102-millimeter hot-mix asphalt concrete (HMAC), with thickness
in millimeters on the horizontal axis and percent frequency on the vertical
axis. The majority of samples have thicknesses of 95 to 115 millimeters, with
frequencies greater than 20 percent. The remaining thicknesses have frequencies
of less than 5 percent. In the second graph, L05B 102-millimeter HMAC is shown,
with thickness in millimeters on the horizontal axis and percent frequency on
the vertical axis. All samples have thicknesses between 85 and 135 millimeters.
Between 95 and 115 millimeters, frequencies are between 25 and 35 percent. The
remaining thicknesses have frequencies of less than 10 percent.

Figure 4. Thickness histograms for the thick HMA layer
(178 millimeters) from tables SPS1_LAYER (construction data) and TST_L05B.
Graphs. The figure consists of two bar graphs. The first graph shows construction
178-millimeter HMAC, and the second shows L05B 178-millimeter HMAC. Both graphs
show thickness in millimeters on the horizontal axis and percent frequency on
the vertical axis. The majority of samples for both graphs have thicknesses of
170 to 210 millimeters, with frequencies between 5 and 35 percent.

Figure 5. Thickness histograms for the thin ATB layer
(102 millimeters) from tables SPS1_LAYER (construction data) and TST_L05B.
Graphs. The figure consists of two bar graphs. The first graph shows
construction 102-millimeter asphalt treated base (ATB), with thickness in
millimeters on the horizontal axis and percent frequency on the vertical axis.
The majority of samples have thicknesses of 95 and 105 millimeters, with
frequencies of 35 and 40 percent, respectively. The remaining samples had
thicknesses of 85, 115, and 125, with frequencies of less than 10 percent. In
the second graph, L05B 102-millimeter ATB is shown, with thickness in
millimeters on the horizontal axis and percent frequency on the vertical axis.
The majority of samples had thicknesses between 95 and 115 millimeters, with
frequencies between 25 and 45 percent.

Figure 6. Thickness histograms for the thick ATB layer
(203 millimeters) from tables SPS1_LAYER (construction data) and TST_L05B.
Graphs. The figure consists of two bar graphs. The first graph shows
construction 203-millimeter ATB, and the second shows L05B 203-millimeter ATB,
with thickness in millimeters on the horizontal axis and percent frequency on
the vertical axis. The majority of samples on both graphs have thicknesses
between 195 and 225 millimeters, with frequencies between 10 and 45 percent.

Figure 7. Thickness histograms for the PATB layer from
tables SPS1_LAYER (construction data) and TST_L05B. Graphs. The figure
consists of two bar graphs. The first graph shows construction 102-millimeter
permeable asphalt treated base (PATB), and the second shows L05B 102-millimeter
PATB, with thickness in millimeters on the horizontal axis and percent
frequency on the vertical axis. The majority of samples on both graphs have
thicknesses between 95 and 115 millimeters, with frequencies between 15 and 58
percent.

Figure 8. Thickness histograms for the 102-millimeter
DGAB layer from tables SPS1_LAYER (construction data) and TST_L05B. Graphs. The
figure consists of two bar graphs. The first graph shows construction
102-millimeter dense graded aggregate base (DGAB), and the second shows L05B
102-millimeter DGAB, with thickness in millimeters on the horizontal axis and
percent frequency on the vertical axis. The majority of samples on both graphs
have thicknesses of 95 and 105 millimeters, with frequencies between 20 and 65
percent.

Figure 9. Thickness histograms for the 203-millimeter
DGAB layer from tables SPS1_LAYER (construction data) and TST_L05B. Graphs.
The figure consists of two bar graphs. The first graph shows construction
203-millimeter DGAB, and the second shows L05B 203-millimeter DGAB, with
thickness in millimeters on the horizontal axis and percent frequency on the vertical
axis. The majority of samples on both graphs have thicknesses between 185 and
215 millimeters, with frequencies around 65 percent at 205 millimeters on each
graph.

Figure 10. Thickness histograms for the 305-millimeter
DGAB layer from tables SPS1_LAYER (construction data) and TST_L05B. Graphs. The
figure consists of two bar graphs. The first graph shows construction
305-millimeter DGAB, and the second shows L05B 305-millimeter DGAB, with
thickness in millimeters on the horizontal axis and percent frequency on the
vertical axis. The majority of samples on the construction graph have
thicknesses between 285 and 315 millimeters, with a frequency of about 55
percent at 305 millimeter thickness. The majority of samples on the second
graph have thicknesses between 295 and 315 millimeters, with a frequency of
about 65 percent at 305 millimeters.

Figure 11. Histogram of air voids measured on the HMA
surface layer. Graph. The figure consists of a bar graph, with percent air
voids on the horizontal axis and frequency on the vertical axis. The frequency
is rather evenly distributed across air voids between 2 and 12 percent, with
frequencies between 5 and 15 percent.

Figure 12. Histogram of air voids measured on the HMA
binder layer. Graph. The figure consists of a bar graph, with percent air
voids on the horizontal axis and frequency on the vertical axis. The frequency
is distributed between air voids of 1 to 13 percent, with frequencies between 2
and 15 percent.

Figure 13. Histogram of air voids measured on the ATB
layer. Graph. The figure consists of a bar graph, with percent air voids on
the horizontal axis and frequency on the vertical axis. The frequency is
distributed between air voids of 2 to 9 percent, with frequencies between 5 and
20 percent.

Figure 14. Histogram of the material passing the number 4
sieve, PATB layer. Graph. The figure consists of a bar graph, with percent
passing number 4 sieve on the horizontal axis and frequency on the vertical
axis. For percent passing of 5, 10, 15, 20, 35, and greater than 50, there were
frequencies of about 30, 52, 5, 5, 3, and 3 percent, respectively.

Figure 15. Histogram of material passing the number 200
sieve, PATB layer. Graph. The figure consists of a bar graph, with percent
passing number 200 sieve on the horizontal axis and frequency on the vertical
axis. For percent passing of 1, 2, 3, 4, and 7, there were frequencies of about
10, 20, 45, 24, and 3 percent, respectively.

Figure 16. Histogram of material passing the number 200
sieve, HMA surface layer. Graph. The figure consists of a bar graph, with
percent passing number 200 sieve on the horizontal axis and frequency on the
vertical axis. For percent passing of 3, 4, 5, 6, 7, and 8, there were
frequencies of about 7, 10, 4, 40, 20, and 20 percent, respectively.

Figure 17. Histogram of material passing the number 200
sieve, ATB layer. Graph. The figure consists of a bar graph, with percent
passing number 200 sieve on the horizontal axis and frequency on the vertical
axis. Samples are rather evenly across 2 to 9 percent passing the number 200
sieve, with frequencies ranging between 5 and 25 percent.

Figure 18. Area of fatigue cracking measured over time
comparing test sections with and without permeable base layers for all SPS-1
projects combined. Graph. The figure consists of a graph of drained
sections versus undrained sections, with the age in years on the horizontal
axis and fatigue in meters squared on the vertical axis. The majority of
fatigue measured occurred on sections between 2 and 6 years old. The undrained
sections showed fatigue on about 16 sections, ranging between 1 and 130 meters
squared. The drained sections showed fatigue on about 37 sections, ranging
between 1 and 190 meters squared.

Figure 19. Total length of transverse cracks measured
over time comparing test section with and without permeable base layers for all
SPS-1 projects combined. Graph. The figure consists of a graph of drained
sections versus undrained sections, with the age in years on the horizontal
axis and transverse cracking in meters on the vertical axis. The majority of
cracking occurred on pavements between 1 and 3 and one-half years old.
Measurable crack lengths ranged between 0 and 85 meters, with no apparent
difference between the drained and undrained sections.

Figure 20. IRI values measured over time comparing test
sections with and without permeable base layers for all SPS-1 projects
combined. Graph. The figure consists of a graph of drained versus undrained
sections, with age in years on the horizontal axis and IRI in meters per
kilometer on the vertical axis. All sections graphed were between 0 and 7 years
of age. The majority of undrained sections and all of the drained sections had
IRI between 0.5 and 2. Approximately 6 of the undrained sections had IRIs greater
than 2.

Figure 21. Rut depths measured over time comparing test
sections with and without permeable base layers for all SPS-1 projects
combined. Graph. The figure consists of a graph of drained versus undrained
sections, with age in years on the horizontal axis and rut depth in millimeters
on the vertical axis. All sections graphed were between 0 and 6 years of age.
Rut depths ranged between 1 and 30 millimeters, with no apparent difference
between drained and undrained sections.

Figure 22. Longitudinal cracking in the wheel paths
measured on different dates for the core test sections of the Alabama project.
Graphs. The figure contains two line graphs showing the Alabama SPS-1
sections constructed March 1, 1993, with survey dates on the horizontal axis and
longitudinal cracking in the wheel path in meters on the vertical axis. The
survey dates begin January 1, 1994, and end December 31, 1999. The first graph
shows 6 test sections with no drainage. Section 1 had crack measurements that increased steadily to 70 meters by
1997 and dropped to 0 by 1998. Section 2 had crack measurements of 15 meters in
1995, then dropped to 0 by 1996, and then increased steadily to 45 meters in
1997 and dropped to 0 by 1998. Section 4 had 1 measurement of 40 meters in
1996. Sections 3, 5, and 6 had no measured longitudinal cracks. The second graph shows 6 sections with
drainage. Sections 7–11 had measurements that start at 0 and jump up to lengths
between 5 meters and nearly 40 meters. Section 12 had no measured cracks.

Figure 23. Longitudinal cracking outside the wheel paths
measured on different dates for the core test sections of the Alabama project.
Graphs. The figure contains two line graphs showing the Alabama SPS-1
sections constructed March 1, 1993, with survey dates on the horizontal axis
and longitudinal cracking outside the wheel path in meters on the vertical
axis. The survey dates begin January 1, 1994, and end December 31, 1999. The
first graph shows 6 test sections with no drainage. All sections had measurements of 0 before and after January 1,
1996, but had lengths as high as 100 meters for most of the sections on January
1, 1996. In the second graph, there were 6 test sections with drainage. In
general, the test sections had longitudinal cracks that were measured around
100 meters in 1994, then measured at 0 in 1995, then measured between 0 and 80
in January 1996, and then at 0 later in 1996.

Figure 24. Transverse cracking measured on different
dates for the core test sections of the Alabama project. Graphs. The figure
contains two line graphs showing the Alabama SPS-1 sections constructed March
1, 1993, with survey dates on the horizontal axis and transverse cracking in
meters on the vertical axis. The survey dates begin January 1, 1994 and end
December 31, 1999. The first graph shows 6 test sections with no drainage. Two
of the sections had transverse cracking measured between 1 and 3 meters in
January 1996 and at 0 at all other survey dates. The remaining sections had
measurements around 0 on all survey dates. In the second graph, there are 6
sections with drainage. In 1994, 1 section had a measurement of 6 meters, and
the other sections had measurements of 0. In 1996, crack lengths between 1 and
3 meters were measured for sections 8, 9, and 10, and 0 for the remaining
sections.

Figure 25. Graphical illustration of the average amount
of fatigue cracking observed on each of the projects, as of January 2000.
Graphs. The figure consists of two graphs. In the first graph, the age in
years is on the horizontal axis and fatigue cracking in meters squared is on
the vertical axis. Measurements for fatigue cracking were around 0 for the
first 2 years, and then increased between 0 and 20 meters squared between 3 and
5 years. Around 6 and 7 years, measurements ranged between 0 and 40 meters
squared. In the second graph, the age in years is on the horizontal axis and
the number of sections with fatigue cracks is on the vertical axis. The number
of sections with cracks is around 0 for the first 2 and one-half years. Beginning
around 3 years, the number of sections increased to 1, and up to 10 by 7 years.

Figure 26. Percentage of the core test sections that
exceed an IRI value of 1.2 meters per kilometer.Graph. The figure
consists of a bar graph. The bar graph shows the experimental site factorial
features on the horizontal axis and percentage of total test sections on the
vertical axis. For coarse-grained, no-freeze; fine-grained, no-freeze;
coarse-grained, freeze; and fine-grained, freeze sites, there were 0, 0, 2.1,
and 31.9 percent of the total test sections, respectively.

Figure 28. Percentage of test sections that exceed an IRI
value of 1.2 meters per kilometer.Graphs. The figure consists of
two bar graphs. The first graph shows HMA surface thickness in millimeter and
base type on the horizontal axis and percent of test sections that exceed an
IRI of 1.2 meters per kilometer on the vertical axis. 178-millimeter ATB sites
were 3.8 percent of test sections. 102-millimeter ATB sites were 13.5 percent.
178-millimeter aggregate sites were 18.4 percent. 102 millimeter and aggregate
sites were 21.1 percent of sites. The second graph shows drainage condition and
base type on the horizontal axis and percent of test sections that exceed an
IRI of 1.2 meter per kilometer. Permeable
ATB sites were 6.7 percent of test sections. Dense ATB were 10 percent.
Permeable aggregate was 20 percent. Dense aggregate was 20 percent.